The present invention relates to sensors and sensing methods, and more particularly, to current sensors and sensing methods suitable for temperature sensing in an integrated circuit (IC), such as a liquid crystal display (LCD) driving IC.
A super twisted nematic (STN) LCD typically is driven by an LCD driving IC. A typical STN LCD has an LCD on/off voltage, i.e., a threshold voltage of the LCD, which changes according to the ambient temperature. Also, the temperature characteristics of the STN LCD may change responsive to various factors, including manufacturing processes and LCD functions. The LCD driving voltage generated by the LCD driving IC preferably has substantially the same temperature characteristics as the STN LCD so that LCD contrast can be maintained substantially constant.
A typical conventional LCD driving IC may only provide a predetermined temperature coefficient in an operating temperature range. If the STN LCD has different temperature coefficients in different operating temperature ranges, LCD contrast in a particular operating range may be affected by an LCD driving voltage that is generated by the LCD driving IC. Therefore, it is desirable that the LCD driving voltages be adjusted for the operating temperature. Accordingly, there is a need for a temperature sensor circuit that can be easily integrated into the LCD driving IC and that is capable of precisely sensing temperature.